I used anki throughout high school for classes and SAT prep - pretty much the main reason I ended up at an ivy league school (now a junior). It was especially helpful for classes like AP Bio / AP US History where there was a ton of pretty obscure stuff to memorize.

It's not so useful in college now that I'm majoring in applied math, but occasionally I'll use it for a humanities class. (throwaway b/c I always use throwaways)